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Abstract:

A method for separating bitumen from crude oil sands comprises subjecting
crude oil sands to vibration selected to cause bitumen to separate from
crude oil sands and filtering the separated bitumen from the crude oil
sands.

Claims:

1. A trough assembly for separating liquid from a colloidal mixture, said
trough assembly comprising: a trough for receiving said colloidal
mixture; at least one vibration source to vibrate said colloidal mixture
to cause liquid to separate from said colloidal mixture; and a filter in
said trough through which separated liquid flows.

2. The trough assembly of claim 1 wherein said trough is substantially
spiral in shape.

3. The trough assembly of claim 1 wherein said at least one vibration
source contacts said colloidal mixture.

4. The trough assembly of claim 3 further comprising a plurality of
vibration sources at spaced locations along said trough.

6. The trough assembly of claim 1 further comprising an anti-dampening
mesh overlying said filter.

7. An apparatus for separating bitumen from crude oil sands, said
apparatus comprising: a plurality of trough assemblies in operative
working vertical series, each of said trough assemblies comprising: a
trough for receiving crude oil sands; at least one vibration source to
vibrate said crude oil sands to cause bitumen to separate from said crude
oil sands; and a filter in said trough through which separated bitumen
flows.

8. The apparatus of claim 7 wherein the vibration source of each trough
assembly is vibrated at a different frequency.

9. A system for excavating crude oil sands and separating bitumen from
crude oil sands, said system comprising: at least one dredge to float in
a liquid reservoir formed in a crude oil sand deposit, said dredge
comprising an excavator for excavating crude oil sands and a separation
apparatus receiving crude oil sands from said excavator and processing
crude oil sands to separate bitumen from said crude oil sands.

10. The system of claim 9 wherein said separation apparatus comprises: a
plurality of trough assemblies provided in cooperative working vertical
series, said each of said trough assemblies comprising: a vibratable
trough for receiving crude oil sands; at least one vibration source to
vibrate said crude oil sands to cause bitumen to separate from said crude
oil sands; and a filter in said trough through which separated bitumen
flows.

11. A method for separating bitumen from crude oil sands comprising:
forming a tarn in a crude oil sands deposit; positioning a dredge in said
tarn; excavating said crude oil sands with said dredge; and processing
the crude oil sands to separate bitumen therefrom.

12. The method of claim 11 wherein said processing is performed on board
said dredge.

Description:

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This U.S. nonprovisional patent application is a divisional
application of and claims the benefit of priority under 35 U.S.C.
§120 from U.S. patent application Ser. No. 11/783,420, filed on Apr.
9, 2007, which claims the benefit of U.S. Provisional Application No.
60/789,922 filed on Apr. 7, 2006, the content of each of which are
incorporated by reference in their entirety.

FIELD OF THE INVENTION

[0002] The following broadly relates to a method of separating liquid from
colloidal mixtures. More specifically, the following relates to a method,
apparatus and system for separating bitumen from crude oil sands.

BACKGROUND OF THE INVENTION

[0003] As is well known, tar sand or crude oil sand deposits are sands
that are impregnated with crude/heavy oil also known as bitumen. Crude
oil sands are typically overlain by various types of overburden media
such as for example, muskeg, clay, soil and gravel. Existing systems of
extracting bitumen from crude oil sand deposits utilize similar practices
to those employed in strip mining of coal. As a result, these systems are
heavily reliant on excavating shovels, draglines, trucks,
gnawing/crushers or sizers to break down large lumps of crude oil sands
to form crushed amassed aggregates. The crushed amassed aggregates are
then transported to an extraction plant at some distance away for further
processing. Alternatively, the crushed amassed aggregate are turned into
slurry and transported to the extraction plant by cycloid feeders (also
known as hydro-transport).

[0004] At the extraction plant, the bitumen is separated from sand and
other media and upgraded for processing. The partially de-oiled sand
residue (also known as tailings) if loose, is transported by truck to a
tailing pond. If the de-oiled same residue is in slurry form, the residue
is pumped by pipeline to the tailing pond.

[0005] These existing practices for extracting crude oil sands and
recovering bitumen require vast amounts of energy and thus, contribute to
excessive greenhouse gas production. These existing extraction practices
also place extensive abrasive wear and tear on the processing equipment
being used. Back-up machinery on stand-by is therefore often required to
replace damaged equipment or components leading to additional expense. In
addition, mining during the winter months is problematic owing to the
freezing of the crude oil sands. These factors make existing practices
for extracting bitumen from crude oil sands inefficient.

[0006] Currently, existing bitumen extraction practices require two
(2)-tons of crude oil sands to recover one (1) barrel of oil and the
process releases into the atmosphere more than ninety (90) Kg of
greenhouse gases per barrel of recovered oil. In addition, up to five (5)
barrels of contaminated wastewater per barrel of recovered oil are
generated. The wastewater is typically dumped into accumulation sites
with the wastewater eventually leaching into ground water. As will be
appreciated from the above, the environmental consequences of existing
crude oil sand extraction practices will clearly continue to violate
Canada's commitments to the Kyoto Protocol to reduce greenhouse gas
emissions by 6% by the year 2012.

[0007] Because the mining of crude oil sands using present day systems is
a costly and inefficient process, there exists a need for more efficient
and reliable systems. It is therefore an object of the present invention
to provide a novel method, apparatus and system for separating bitumen
from crude oil sands.

SUMMARY OF THE INVENTION

[0008] Accordingly, in one aspect there is provided a method for
separating bitumen from crude oil sands comprising:

[0011] According to another aspect there is provided a trough assembly for
separating liquid from a colloidal mixture, said trough assembly
comprising:

[0012] a trough for receiving said colloidal mixture;

[0013] at least one vibration source to vibrate said colloidal mixture to
cause liquid to separate from said colloidal mixture; and

[0014] a filter in said trough through which separated liquid flows.

[0015] According to yet another aspect there is provided an apparatus for
separating bitumen from crude oil sands, said apparatus comprising:

[0016] a plurality of trough assemblies in operative working vertical
series, each of said trough assemblies comprising: [0017] a trough for
receiving crude oil sands; [0018] at least one vibration source to
vibrate said crude oil sands to cause bitumen to separate from said
media; and [0019] a filter in said trough through which separated bitumen
flows.

[0020] According to still yet another aspect there is provided a system
for excavating crude oil sands and separating bitumen from crude oil
sands, said system comprising:

[0021] at least one dredge to float in a liquid reservoir formed in a
crude oil sand deposit, said dredge comprising an excavator for
excavating crude oil sands and a separation apparatus receiving crude oil
sands from said excavator and processing said crude oil sands to separate
bitumen from said crude oil sands.

[0022] According to still yet another aspect there is provided a method
for separating bitumen from crude oil sands comprising:

[0023] forming a tarn in a crude oil sand deposit; positioning a dredge in
said tarn; excavating said crude oil sand with said dredge; and
processing the crude oil sand to separate bitumen therefrom.

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Embodiments will now be described, by way of example only, with
reference to the attached drawings, wherein:

[0025] FIG. 1 is a side elevation view of a recovery dredge in a tarn;

[0026] FIG. 2 is a perspective view of the recovery dredge of FIG. 1;

[0027] FIG. 3a is a perspective view of first and second churns forming
part of the recovery dredge of FIG. 1;

[0028]FIG. 3b is a side elevation view of a crude oil sand separation
apparatus forming part of the recovery dredge of FIG. 1;

[0029] FIG. 4 is a side elevation view, partly in section, of a trough
assembly comprising a separation trough;

[0047]FIG. 16 is a side elevation view of another embodiment of a
recovery dredge for use in deep oil sand mining;

[0048] FIG. 17 is a flowchart showing the steps performed during
separation of water from sewage; and

[0049]FIG. 18 is a side elevation view of a system for separating water
from sewage.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0050] The following broadly relates to a method, apparatus and system for
separating liquid from a colloidal mixture and in particular, bitumen
from crude oil sands. One or more self-contained mobile recovery dredges
are used to harmonically and chemically separate bitumen from crude oil
sands at the site of the tar/crude oil sand deposit. Embodiments will now
be described more fully with reference to the FIGS. 1 to 19.

[0051] Shown in FIGS. 1 and 2 is a side elevation view and a perspective
view, respectively of a crude oil sand recovery dredge 110 in an
artificial tarn or reservoir 112 formed in a crude oil sand deposit to be
excavated. Dredge 110 comprises a deck 113 supported on pontoons 114 and
floats on water or brackish water in tarn 112. Dredge 110 also comprises
a swingable dredge cutting head 116 (otherwise known as an oil sand
excavator) at its forward end that is supported by a powered gantry 118
mounted on the deck 113. The cutting head 116 has cutting and grinding
surfaces that are used to excavate crude oil sands 120. Crude oil sands
120 comprise a non-homogenous mixture of bitumen and other types of media
such as, but not limited to, clay and sand. The excavated crude oil sands
120 are drawn up along a conveyor belt 122 with any excess water being
removed by filtration and gravity-assisted drainage. Conveyor belt 122
feeds the excavated crude oil sands to a crude oil sand processing
apparatus 123 generally centrally positioned on the deck 113. Processing
apparatus 123 processes excavated crude oil sands to separate bitumen
from the remainder of the crude oil sands (i.e. tailings). A swingable
dragline 186 extending from the rear end of the dredge 110 is also
supported by a powered gantry 118 mounted on the deck 113. The dragline
186 delivers the tailings into the tarn 112 to backfill the tarn as the
dredge 110 advances.

[0052] In this embodiment, the crude oil sand separation apparatus 123
comprises a pair of churns 126 and 130 disposed above a distribution
hopper 124. Hopper 124 communicates with a plurality of separation
apparatuses 134, each separation apparatus 134 comprising a plurality of
trough assemblies 136 connected in series. Further specifics of the crude
oil sand separation apparatus 123 will now be described.

[0053] Turning to FIG. 3a, the churns 126 and 130 are better illustrated.
As can be seen, conveyor belt 122 feeds the excavated crude oil sands
into the first churn 126 via a plurality of chutes 128 (otherwise known
as deflectors). First churn 126 heats the crude oil sands 120 with hot
water by way of a steam jacket or a calorifier to soften the crude oil
sands 120. The first churn 126 also acts as a dehumidifier for the crude
oil sands 120 to remove any excess moisture in the crude oil sands 120.
Dehumidification in this embodiment is accomplished using compressed
carbon dioxide (CO2) gas (e.g. at about 20 bar) which forms dry-ice
in an auto-refrigeration process. The first churn 126 may also contain
infrared systems that serve to dry the crude oil sands 120. The crude oil
sands 120 are then fed into the second churn 130 where various extraction
agents such as caustic soda (otherwise known as NaOH) are used to
catalyze the separation of bitumen from crude oil sands 120.

[0054] As can be seen in FIG. 3b, after exiting the first and second
churns 126 and 130, the resultant colloidal mixture of crude oil sands
120 is then fed to the distribution hopper 124. Crude oils sands 120 from
the distribution hopper 124 are then fed in parallel to a plurality of
distribution troughs 132. Each distribution trough 132 is operatively
coupled to one of the separation apparatuses 134. In this embodiment,
each separation apparatus 134 comprises three (3) trough assemblies
connected in series although fewer or more trough assemblies may be
employed. Each trough assembly 134 employs at least one of harmonic and
chemical techniques to separate bitumen from crude oil sands.

[0055] Turning now to FIGS. 4 to 10, one of the trough assemblies 136 is
better illustrated. As can be seen, each trough assembly 136 comprises a
downwardly depending separation trough 142 that is adapted to receive
crude oils sands 120 from a top or head portion 144. Separation trough
142 spirals around and is mounted to a central support stem 168 by
radially extending support members 166. Separation trough 142 has an
outer wall 146 and an inner wall 148. Spaced inwardly from inner wall 148
is a mesh screen 150. Mesh screen 150 acts as a filter and divides the
interior of the separation trough 142 into an oil sand receiving channel
152 and a bitumen collection channel 154.

[0056] Adjacent the bottom portion 156 (otherwise known as tail portion)
of trough assembly 136 there is provided a bitumen discharge outlet 158
and a de-oiled media (otherwise known as the dry filtrate) discharge
outlet 160. Bitumen discharge outlet 158 directs extracted bitumen
collected in collection channel 154 to a bitumen storage vessel (not
shown) on dredge 110 prior to the delivery to an off-site facility for
further processing. De-oiled media discharge outlet 160 directs the
de-oiled media either to the next trough assembly in the series or to the
dragline 186.

[0057] While an open-topped trough assembly 136 is shown, it will be
understood that depending on the volume of crude oil sand 120, it may be
desirable to fit a retaining cap over the separation trough 142 to
inhibit spilling of crude oil sands from out of the separation trough
during the bitumen separation process.

[0058] As shown in FIGS. 6a to 6c, exciters 172 are positioned within and
along the channel 152 of the separation trough 142 at spaced locations.
As a result, during operation, the exciters 172 are immersed in the flow
of crude oil sands 120. The exciters 172 are controlled so that they
vibrate at a frequency that is generally matched to the resonant
frequency or natural frequency mode of vibration (or "harmonic" thereof)
of the bitumen in the crude oil sands to assist in separating bitumen
from the crude oil sands 120.

[0059] As shown in FIGS. 7a to 7c, torsional vibration vanes 174 are
placed between the exciters 172. The vibration vanes 174 are vibrated in
a manner to create anti-protuberance nodules which oscillate between
large negative/positive displacements. The torsional vibration vanes 174
also serve to increase the amount of shear and gravity-assisted tumbling
of crude oil sands 120. Although, the torsional vibration vanes 174 are
depicted in FIGS. 7b and 7c as being curved pairs and partially embedded
in the separation trough 142, it will be appreciated by those skilled in
the art that the vibration vanes 174 may take any suitable form that
increases the amount of shear and gravity-assisted tumbling of crude oil
sands 120.

[0061] As described above, crude oil sands 120 are a non-homogeneous
mixture and therefore, it is useful to monitor the separation process and
measure a number of the physical properties of the crude oil sand 120 in
order to adjust in real-time, the operating frequencies of the exciters
172, torsional vibration vanes 174 and linear vibrating drives 176. Some
of these physical properties may be, but are not limited to temperature,
mass, viscosity, speed of flow and depth of the crude oil sand 120 in the
separation trough 142. The physical properties of liquids may be
monitored and measured by various sensory arrays or detection devices
well-known by those skilled in the art positioned at locations along the
trough assembly.

[0062] For example, as can be seen in FIG. 6a, rat's tail detectors 178
for measuring speed of flow are shown. Each detector 178 is an
incremental ratchet-toggling switch where the switch's rotating detent
gear is attached to a rigid, plastic coated rod hanging down into the
separation trough 142. The rod is spring loaded to a forward detent
position corresponding to zero flow but moves by flow drag toward a rear
position. In this embodiment, a rat's tail detector 178 is placed ahead
of each exciter 172 to measure flow properties of the crude oil sands
120. A representative rat's tail detector 178 is made by Square D, a
brand of Schneider Electric Company and other known manufacturers include
Allan Bradley. The output of the detectors 178 is applied to a computer
(not shown) executing "watchdog" software. The computer "watchdog"
software in response to the output of the detectors 178 changes the
output harmonics of the resonant frequency-imparting exciters 172,
torsional vibration vanes 174 and linear vibrating drives 176.

[0063] It will be appreciated that separation trough 142 may exert a
dampening effect to the harmonics created by the various
vibration-imparting devices. To substantially retain harmonic energy
within separation trough 142, an anti-dampening mesh 180 is placed
overtop and adjacent to mesh 150 as shown in FIG. 9.

[0065] As shown in FIG. 10, the pressure-pulse-wave incursion is expected
to result from a combination of force vectors where vector y=about 3 Hz
to about 240 Hz; R, is torsional force=about 175 Hz to about 750 Hz;
vector x=about 500 Hz to about 1.1 KHz; vector z=about 3 KHz to about 5.5
KHz; and resonant frequency f=1.75 GHz to about 2.2 GHZ. The collective
resonant frequencies may range from about 25 Hz to about 2.2 GHz,
however, it will be appreciated by one skilled in the art would that the
most suitable range of resonant frequencies will depend on variables such
as, but not limited to the amount, temperature, pressure, composition and
other physical properties of crude oil sands 120.

[0066] Before operating the dredge, tarn 112 is initially excavated using
existing excavation methods to form a pit and the pit is filled with
water. Tarn 112 may alternatively be filled with brackish water in the
winter months to prevent freezing of tarn 112. Sulphur may be added to
the water or brackish water to assist in the lubrication of submersed
moving dredge parts. Once filled, the dredge 110 is floated into tarn
112. Dredge 110 progresses on its own power or is moved by other means to
the leading edge of tarn 112. Dredge 110 may be guided using steering
spuds 182, however, one skilled in the art will appreciate that the
dredge 110 may be steered by any known means of steering. The speed of
dredge 110 is dependent upon, among other things, temperature and may be
in the order of about 10-25 feet/24 hour day.

[0067] Once the dredge 110 is properly positioned within the tarn 112, the
dredge cutting head 116 is actuated and begins its oscillating motion.
Crude oil sands 120 that are excavated using the dredge head 116 are
delivered to the first churn 126 where the crude oil sands 120 are
dehumidified with CO2 and/or infrared to begin the process of
bitumen separation.

[0068] From the first churn 126, crude oil sands 120 are then fed into the
second churn 130 containing various extraction and/or processing agents.
The extraction agents may be selected from the group consisting of sodium
hydroxide, boric acid, nitric oxide and sulphur dioxides. From the second
churn 130, the pre-treated crude oil sands are directed into distribution
hopper 124. One skilled in the art will understand that there may be as
many or as few churns as required to make crude oil sands 120 into a
consistency suitable for the separation of bitumen. Distribution hopper
124 divides the crude oil sands 120 and conveys them to the distribution
troughs 132, each of which is in operative communication with one of the
separation apparatuses 134.

[0069] In each separation apparatus 134, to separate bitumen from crude
oil sands 120, the exciters 172, vibration vanes 174 and linear vibrating
drives 176 of the first trough assembly 136 vibrate and control the flow
of crude oil sands to separate bitumen from crude oil sands 120. By
matching the vibration generally to the resonant frequency of the bitumen
in the crude oil sands, the separation of the bitumen begins resulting in
the loosened bitumen flowing through the mesh 180 and mesh screen 150 and
collecting in bitumen collection channel 154. This separation is aided
further by the cross-shear experienced by crude oil sands 120 as they
tumble in resemblance to a rolling avalanche to tail portion 156 of first
trough assembly 136. The vibrational vanes 174 also serve to increase the
amount of shear experienced by crude oil sands 120 as they move downward
through trough assembly 136. The separated bitumen exits the first trough
assembly 136 via bitumen discharge outlet 158 of first trough assembly
136.

[0070] Crude oil sands 120 exiting the first trough assembly 136 are
delivered to the second trough assembly 136 in the series. The crude oil
sands are then subjected to a second round of separation. In this round
of separation, the crude oil sands 120 are treated with various
extraction agents and/or processing agents. The extraction agent may be
NaOH which acts to crack crude oil sands 120 by breaking the long chain
hydrocarbons into smaller chain hydrocarbons. One skilled in the art
would readily understand that any other suitable cracking agents may also
be used. The exciters 172, vibrational vanes 174 and linear vibrating
drives 176 of the second trough assembly similarly vibrate and control
crude oil sand flow in a manner to separate further bitumen from crude
oil sands. The separated bitumen is collected by the bitumen collecting
channel 154 and delivered to the bitumen discharge outlet 158. The crude
oil sands exiting the second trough assembly are then delivered to the
last trough assembly in the series. Crude oil sands 120 are then
subjected to the third round of separation. In particular, the crude oil
sands 120 are treated with additional extraction agents and/or processing
agents, such as for example thinning agents (e.g. naphtha). The exciters
172, vibrational vanes 174 and linear vibrating drives 176 vibrate and
control the flow of crude oil sand in a manner to separate bitumen from
crude oil sands.

[0071] As mentioned above, crude oil sands contain a number of different
media, such as for example clay, sand and viscid bitumen-lacker oils.
Clay is obtained from the weathering of Feldspar, a very common form a
rock/clay and has the chemical formula
Al2O3.2SiO2.2H2O. To aid in the harmonic separation
of bitumen from clay in crude oil sands 120, extraction agents including,
but not limited to, sodium hydroxide and liquid CO2, may be added to
help create shearing causing additional dispersion and flocculation. Sand
is finely divided rock comprising granular particles ranging usually from
0.004 mm to 0.062 mm. The most common constituents of sand is silica or
silicon dioxide in the form of quartz with considerable Feldspar content.

[0072] Bitumen that is collected by the bitumen collection channels 154 of
the trough assemblies is stored on board the dredge 110 in the bitumen
storage vessels (not shown). The stored bitumen is then ready for
delivery to an off-site extraction facility for further processing. The
de-oiled media that is discharged from the dry filtrate discharge outlet
160 of the last trough assembly of each separation apparatus is removed
from dredge 110 by the dragline 186 to backfill the tarn 112 as the
dredge 110 moves in the forward direction.

[0073] FIG. 11 is a flowchart illustrating generally the steps described
above.

[0074] One skilled in the art would understand that during bitumen
extraction, any combination of extraction agents and/or processing agents
may be added to any one or all of trough assemblies 136 to assist in
extraction of the bitumen from crude oil sands 120. The substantially
de-oiled media may be removed at the termination of each round of the
bitumen separation process to further concentrate the remaining oil-laden
sand. Any substantially de-oiled media that serves additional commercial
purposes may be harvested during the bitumen separation process. An
example would be Kaolin clay having the composition of
Al2Si2O5(OH)4. Kaolin clay (Kaolinite) obtained from
crude oil sands 120 has commercial importance in the pharmaceutical;
cosmetic; and the ceramics industries. One skilled in art would readily
understand how Kaolin clay might be harvested during the bitumen
separation process. For example, the lighter Kaolin clay may be skimmed
off the surface of the crude oil sands during the process of bitumen
separation.

[0075] Although each trough assembly is described as comprising exciters
172, vibrating vanes 174 and linear vibrating devices 176, the trough
assemblies 136 may comprise a subset of these resonant-frequency
imparting devices. Also, if desired, the trough assemblies in each
separation apparatus 134 may comprise different combinations of
resonant-frequency imparting devices. Of course, different vibration
devices or mechanisms to impart vibration to crude oil sands in the
separation troughs 142 of the trough assemblies can be employed. For
example, turning to FIG. 12 and alternative trough assembly 136 is shown.
In this embodiment, the support stem 168 is mechanically coupled to a
central stem vibrator (not shown). The central stem vibrator can be any
known device which causes axial vibration of the central support stem 168
resulting in causing vibration of trough assembly 136 and thus, urging
the crude oil sands 120 down trough assembly 136. Trough assembly 136 is
also provided with a number of resonant frequency-imparting devices 170
fixed to the outside wall of the separation trough. Resonant
frequency-imparting devices 170 produce in vibratory to assist in
separating bitumen from the crude oil sands 120. The resultant effect is
that the crude oil sands traveling down the trough assembly 136
experience dual vibrating harmonic interference or beat frequency in a
heterodyne fashion. In this embodiment, each trough assembly in the
series produces vibration at a different frequency that substantially
matches the natural frequency mode of vibration of a different particular
media or consistent of the crude oil sands 120.

[0076] In the embodiment of FIG. 12, the natural frequency mode of
vibration is calculated using the following formula. Treating the trough
assembly as a flexible-mass system to which an external force F0
cos(ωt) is applied, where F0 and ω are constants, the
equation of motion is then

my"+ry'+ky=F0 cos(ωt)

y=Rez

with

m/z"+yz'+kz=F0 exp(iωt)

a trial solution,

z=B exp(iωt)

The roots of the characteristic equation will all have negative real
parts. One gets,

B = F o - m ω 2 + γω + k = F o
m ( ω o 2 - ω 2 ) + γω
##EQU00001##

[0077] We want to write this in a polar representation

B=Rexp(-iδ)

where

R>0. Thus

R = B = F o m ( ω o 2 - ω 2 ) +
γω = F o Δ ##EQU00002##

where

Δ= {square root over
(m2(ω02-ω2)2+γ2ω.su-
p.2)}

cos δ=m(ω02-ω2)/Δ

sin δ=γω/Δ

where

ωo= {square root over (k/m)}

where [0078] m is the system mass [0079] k is the system stiffness
(variables) [0080] γ is the system damping (variables) when the `R`
amount is controlled and the range is 0-3 mm, a value of about 247 Hz is
obtained for ω.

[0081] It will be understood that other methods to calculate the range of
resonant frequencies (or natural frequency mode of vibration) of media in
crude oil sands may be readily conceived by one skilled in the art.

[0082] Although, it has been shown that trough assembly 136 has a
downwardly depending circular, smooth spiral configuration, it will be
readily apparent that the trough assembly 136 need not have a
substantially smooth shape. As can be seen in FIGS. 13a and 13b, trough
assembly 236 may also have a substantially faceted spiral configuration.
Furthermore, one skilled in the art will understand that trough assembly
136 need not be a downwardly depending spiral having an inverse slope.
Rather, the trough assembly 136 may have a helical shape or may rest in a
substantially horizontal plane so long as vibration can be applied to
crude oil sands to harmonically separate the bitumen from the crude oil
sands 120.

[0083] In cross-section, the separation trough 142 of each trough assembly
136 has been shown to be substantially U-shaped, however, one skilled in
the art will understand that trough 142 need not have a U-shape and that
it may have a V-shape or any shape that can suitably contain crude oil
sands 120. Trough 142 may also be made to have an internal diameter (d)
that decreases from head portion 144 to tail portion 156 to compensate
for any decreases in the volume of crude oil sands 120 as bitumen is
removed during the harmonic separation process.

[0084] Mesh screen 150 can be an inconel or cobalt wire mesh or similar
material and anti-dampening mesh 180 can be made of nylon. One skilled in
the art will understand that mesh screen 150 and anti-dampening mesh 180
may be made of any material that is durable and can withstand large
vibrational and frictional forces and the tolerance pitch dot size can
range from about 0.001 to 0.02 inches.

[0085] Shown in FIGS. 14a and 14b is another embodiment of separation
apparatuses comprising trough assemblies 136 arranged in a compact
inter-leafed configuration designed to maximize the amount of available
area on dredge 110. It will also be readily appreciated that there may be
fewer or greater than three (3) trough assemblies 136 in a vertical
series in any given separation apparatus 134 and that the number of loops
in the trough assemblies 136 may vary.

[0086] As shown in FIG. 15, a series of identical dredges 110 lined up
astern to more efficiently excavate a larger area is depicted. In this
embodiment, the cutting heads116 and draglines 186 of the dredges are
swingable between angles of repose shown by the broken lines, however,
one skilled in the art would readily understand that dredge head 116 and
dragline 186 may also be fixed. The gantries 118 allow the depths of the
cutting heads to be adjusted to permit dredging at considerable depths
below the surface. For example, dredging depths around 80 meters below
the surface are achievable.

[0087] As mentioned above, the bitumen in bitumen storage vessels on-board
dredge 110 is ready for delivery to an off-site extraction facility for
further processing. If desired an umbilical transfer line (not shown) may
be provided that sits on a gantry mounted on the deck 113 and that
protrudes perpendicular from the centerline of travel of the dredge 110
for discharging the bitumen to wheeled tankers moving alongside the tarn,
or to a looped pipeline for pick-up.

[0088] It will be appreciated that since dredge 110 is an enclosed system,
any extraction and/or processing agents that are used during the bitumen
separation process can also be reused by employing on-board extraction
agent recyclers (not shown). One skilled in the art will readily
understand that on-board extraction agent recyclers can comprise standard
chiller/centrifuge and recovery equipment. Furthermore, the source of the
CO2 used during the crude oil sand 120 dehumidification process, may
be from CO2 sequestered from the atmosphere using air carbon capture
and/or from exhaust gases produced by ancillary mechanical equipment
(e.g. diesel-electric generators, Ward Leonard sets and engines etc. . .
. ) and combined in CO2 compressor collectors. Any excess CO2
may be combined with calcium (to form calcium carbonate or otherwise
known as talc) and released into the tailings to act as a meek
stabilizing fertilizer.

[0089] Dredge 110 may also be provided with water pumping systems to pump
water to-and-from tarn 112 for use with operational equipment as well as
water clarifying systems. It will be appreciated by one of skill in the
art that tarn 112 may contain tramp oil, which is residue oil floating on
the surface of tarn 112. The tramp oil may be collected by skimming off
the tramp oil from the surface of tarn 112 and added to an oil collection
vessel on board the dredge 110. Collected tramp oil may be processed and
refined using known methods to one of skill in the art. Water may be
pumped into the dredge 110 from below the surface of tramp oil present in
tarn 112. The water that is pumped on board may be used during the crude
oil sand excavating process as a high pressure cutting tool 184 as shown
in FIGS. 1 and 2. Water forced out of cutting tool 184 at extremely high
pressures erodes and aids the breaking up of the crude oil sands 120.
Water pumped into the dredge 110 may also be used as a partial means of
propulsion and steering for dredge 110. The dredge 110 may also be
provided with water cooling systems (not shown) to cool the cutting head
116 and any onboard pumps, compressors, diesel-electric generators and/or
electric motors and other ancillary devices (not shown). The dredge 110
may also be provided with water heating systems (not shown) to heat the
water for use during the bitumen separation process.

[0090] Turning now to FIG. 16, a subterranean harvester 210 for use in
deep mining processes is shown. As can be seen, harvester 210 is adapted
for use in underground crude oil sand mining operations. The subterranean
harvester 210 is lowered below ground via mining collection shafts and
employs a tunnel boring head 216 and a suitable dragline. Crude oil sands
excavated using boring head 216 are processed by a crude oil sand
processing apparatus similar to that described above. The separated
bitumen is then removed from the mine using conventional means such as
for example, a transfer line 188.

[0091] It will be readily appreciated that separation apparatus 134 may be
considered an independent platform and thus, the separation apparatus 134
may be utilized in different applications, and may be moveable from one
system to another system. In other words, separation apparatus 134 may be
moved, for example, from mobile dredge 110 to subterranean harvester 210
and visa versa.

[0092] In summary, a novel self-contained mobile dredge that employs
harmonic and chemical technique to separate bitumen from crude oil sands
at the site of the tar/crude oil sand deposit is described. The mobile
dredge obviates the need for shovels for the excavation process and
trucks to deliver the crude oil sands to an offsite processing facility
and to return the partially de-oiled sand residue to a tailings location.

[0093] The mobile dredge is a significant advancement over current systems
for the extraction of bitumen from crude oil sands because the mobile
dredge obviates the need for expensive heavy excavation machinery and
hauling systems comprising trucks, draglines, hydro-transport lines and
pipelines. Also, being a self-contained system, the mobile dredge system
is extremely energy efficient because it permits the recycling of the
numerous extraction and/or processing agents employed during the bitumen
extraction process. The mobile dredge also provides for the harvesting
and collection of commercially useful particulate matter or media in
crude oil sands. Furthermore, the self-contained mobile dredge is
ecologically conscious because it significantly avoids the need to
produce separate tailings ponds and reduces greenhouse gas.

[0094] It will be readily apparent that the method and the separation
apparatus for separating bitumen from crude oil sands may be used in the
separation of a liquid from other colloidal mixtures. For instance, water
may be separated from colloidal solutions, such as for example, the
de-watering of sewage, dairy products, paints, adhesives, latex rubber
and biological fluids such as blood plasma. For example, water may be
separated from colloidal solutions such as sewage in accordance with the
method as outlined in FIG. 17. As can be seen in FIG. 18, sewage from a
drag pit 312 in need of de-watering is collected by a drag chain 316 and
via a distribution hopper 324 is placed on a single trough assembly 336
similar to that described above with reference to FIGS. 4 to 10.

[0095] The above-described embodiments are intended to be examples and
alterations and modifications may be effected thereto, by those of skill
in the art, without departing from the spirit and scope of the invention
as defined by the claims appended hereto.